1. Field of the Invention
The present invention concerns light irradiating devices which produce treated liquids that are free of bacteria, organic matter or harmful substances, etc., by performing light irradiation treatments such as eradication of bacteria, oxidative decomposition of organic matter or decomposition of harmful substances, etc., in said liquids.
2. Background of the Prior Art and Related Information
In conventional light irradiating devices, light-transmitting tubes containing (e.g.) ultraviolet lamps as light irradiating lamps are installed one by one at intervals inside a housing, and a liquid containing bacteria, organic matter or harmful substances, etc., which is caused to flow into said housing is subjected to an ultraviolet irradiation treatment, thus causing eradication of the aforementioned bacteria, oxidative decomposition of the aforementioned organic matter or decomposition of the aforementioned harmful substances, etc., so that a treated liquid which is free of said bacteria, organic matter or harmful substances, etc., is obtained. Such treated liquids can then be used in various industrial fields.
However, in the case of such conventional ultraviolet irradiating devices, contaminants such as organic matter, etc., present in the liquid being subjected to the ultraviolet irradiation treatment adhere to the outside surfaces of the light-transmitting tubes containing the aforementioned ultraviolet lamps during said treatment; this adhesion of contaminants leads to problems such as a drop in the purity of the treated liquid and a drop in the ultraviolet irradiation efficiency, etc.
Accordingly, in conventional ultraviolet irradiating devices, the following type of cleaning operation is necessary: the ultraviolet irradiation treatment is interrupted (and in some cases, the ultraviolet irradiating device is disassembled), and the light-transmitting tubes with adhering contaminants are removed one by one and cleaned by hand; then, after this cleaning is completed, the light-transmitting tubes are re-attached to the ultraviolet irradiating device one by one. As a result, this cleaning operation requires considerable time and expense, leading to a drop in the efficiency of the ultraviolet irradiation treatment.
Conventional ultraviolet irradiating devices also include devices in which frames to which a plurality of light-transmitting tubes containing ultraviolet lamps are attached are installed inside a housing. However, in devices of this type, no mechanism for cleaning ultraviolet light-transmitting tubes with adhering contaminants is provided; instead, it is necessary to perform a cleaning operation in which the frames are removed from the device and the light-transmitting tubes attached to the respective frames are manually cleaned one by one, after which the frames with attached light-transmitting tubes are re-attached to the device following the completion of cleaning. Thus, such devices are the same as other conventional devices in terms of suffering from the aforementioned drawbacks.
Furthermore, in cases where it is necessary to replace ultraviolet lamps which have burned out or become damaged during the ultraviolet irradiation treatment of a liquid, such replacement is commonly accomplished by disassembling the device, removing the ultraviolet lamps one by one and replacing said lamps by hand. No operation in which ultraviolet irradiating modules consisting of light-transmitting tubes containing ultraviolet lamps are removed from the device as freely detachable integral units (so that the aforementioned burned-out or damage ultraviolet lamps can be simply replaced) is performed. Accordingly, such devices still suffer from the aforementioned drawback in terms of ultraviolet lamp replacement.
Furthermore, ultraviolet irradiating devices which have been used experimentally include devices in which a! a cleaning body to which a brush, etc., is attached is fit over a screw shaft installed inside a device containing a single ultraviolet lamp equipped with a light-transmitting tube (with said cleaning body being installed so that screw type motion of said cleaning body is possible), and b! the aforementioned cleaning body is caused to perform a reciprocating motion along the outside surface of the aforementioned light-transmitting tube by causing the aforementioned screw shaft to rotate, thus causing contaminants adhering to said light-transmitting tube to be stripped away so that said light-transmitting tube is cleaned.
However, such conventional ultraviolet irradiating devices with a cleaning mechanism which uses a cleaning body are devices in which a single ultraviolet lamp equipped with a light-transmitting tube is installed inside the device. Such devices have not included devices in which a plurality of ultraviolet lamps equipped with light-transmitting tubes are simultaneously and automatically cleaned. Furthermore, in such conventional ultraviolet irradiating devices, the screw shaft attached to the light-transmitting tube and the cleaning body with an attached brush, etc., are formed as an integral unit. Accordingly, in cases where a burned-out or damaged ultraviolet lamp is to be replaced, it is necessary to disassemble the screw shaft and cleaning body (with attached brush, etc.), and then to remove the ultraviolet lamp from the housing so that said lamp can be replaced. Thus, an extremely laborious operation is required, so that the treatment efficiency is poor.